some css lint fixes

src/app/styles.module.scss

@@ -46,7 +46,7 @@
         font-weight: 400;
         text-decoration: none;
         color: $color-orange;
-        text-shadow: 2px 2px 2px black;
+        text-shadow: 2px 2px 2px $color-black;
     }
 }
 
@@ -54,11 +54,3 @@
     font-size: 14px;
     color: #555;
 }
-
-.header {
-    color: inherit;
-    display: block;
-    overflow: auto;
-    padding: 15px;
-    text-decoration: none;
-}

src/theme/form.scss

@@ -3,7 +3,7 @@
 button {
     padding: 5px 20px;
     background-color: $color-orange;
-    border: none;
+    border: 0;
     color: $color-white;
     border-radius: 14px;
     font-weight: bold;

src/theme/variables.scss

@@ -1,7 +1,8 @@
 $color-white: #fff;
+$color-black: #000;
 $color-orange: #ea4d0a;
 
-$border-large: 4px solid black;
-$border-thin: 2px solid black;
+$border-large: 4px solid $color-black;
+$border-thin: 2px solid $color-black;
 
 $font-pel: "Grobold";